1. Field
The present disclosure relates to a heat treatment apparatus and a heat treatment method using the same.
2. Description of the Related Technology
A flat panel display (FPD), such as an organic light emitting display device (OLED) or a liquid crystal display device (LCD), employs a thin film transistor (TFT). In general, formation of a TFT includes depositing amorphous silicon (a-Si) on a transparent substrate formed of glass or quartz, dehydrogenating the a-Si, implanting impurity ions to form a channel, and forming a semiconductor layer by crystallizing the a-Si into polycrystalline silicon (poly-Si) using a heat treatment process.
In this case, the semiconductor layer, which constitutes a source, a drain and a channel of the TFT, is formed by depositing an a-Si layer on the transparent substrate, such as a glass substrate, using a chemical vapor deposition (CVD) process.
Thereafter, a crystallization process is carried out. Specifically, the a-Si layer with low electron mobility is heat-treated and crystallized into a poly-Si layer with high electron mobility. Various crystallization methods may apply to the crystallization process. These methods apply energy (i.e., heat) to the a-Si layer to crystallize the a-Si layer into the poly-Si layer.